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Three Part Question

In [emergency department patients with chest pain who have had a recent negative cardiac stress test] what is the [prevalence] of [significant coronary artery disease]?

Clinical Scenario

A 40 year old male with a negative cardiac stress test performed 1.5 years ago presents to the emergency depart with symptoms consistent with ACS.

Search Strategy

Medline 1946-05/13 using OVID interface, DARE database, Cochrane Library (2013), PubMed clinical queries
[(exp Emergency Medical Services/ or exp Emergency Service/hospital) AND (exp Chest Pain/ or exp Acute Coronary Syndrome or exp Coronary Artery Disease) AND (exp Excercise Test)]. Limit to English language

Search Outcome

129 papers were identified; of which three answered the clinical question. Two clinical studies included patients who presented to the ED with chest pain and had a prior negative cardiac stress test. One study was a recent meta-analysis examining the diagnostic accuracy or exercise stress testing for CAD compared to angiography.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Walker, Jonathan DO. Galuska, Michael MD, Vega, David MD 2010 USA	164 patients presenting to the Emergency Department with chief complaint of chest pain, with a recent negative cardiac stress test in the past 3 years and hospital admission	Retrospective chart review	Frequency of significant CAD in patients presenting to the ED with recent negative stress test	Negative non-invasive cardiac stress tests should not be used to rule out CAD. Patients with recent negative tests are just as likely to have CAD as patients with inconlusive tests.	This paper had a number of weaknesses. First, it is a retrospective chart review from a single institution, which may make its findings not applicable to other populations. Second, only admitted patients were assessed for adverse cardiac events, which introduces selection bias. Finally, the sample size was small with only 164 patients.
Rebecca H Nerenberg BS, Frances S. Schofer PhD, Jennifer L. Robey RN, Aaron M. Brown BS, May 28 2006 USA	Patients 30 years or older who presented to the ED with chest pain with the potential to be ACS	Prospective cohort study	Primary outcome was the emergency physician disposition decision. The secondary outcome was a composite 30-day cardiovascular event including death, nonfatal AMI, percutaneous intervention or CABG	Patients without prior stress tests and patients with normal prior stress tests were admitted for possible ACS at the same rate and had the same 30 day cardiovascular event rates.	This study had several weaknesses. The first is that a small cohort of patients were enrolled during hours when trained research assistants were not in the hospital, which may introduce selection bias as they may be different than patients enrolled by the trained research assistants. Next, the study did not differentiate the timing of prior stress testing. A Prior stress test that was 1 week old was grouped together as being the same as a test that was 5 years old. Finally, the study population is from a single ED, which may make the results not applicable to other populations.
A. Banerjee1, D.R. Newman, A. Van den Bruel, C. Heneghan May 2012 USA	Prospective studies comparing exercise stress testing with a reference standard of coronary angiography in patients without known CAD	Meta anaylsis of current literature looking at diagnostic accuracy of cardiac stress testing.	Primary outcome is the diagnostic accuracy of stress tests	Result shows that while a positive stress test serves as a good indicator of the need for angiography, a negative test cannot rule out CAD	First, a major weakness of the paper lies in the inherent weaknesses of the indivdual studies. Next, prior knowledge of results within studies brings a possible bias into question. Finally, the review was pointed toward excercise stress testing in relation to CAD, however, included studies had endpoints which ranged from heart cath to post mortum reports which could make the results less valid.

Comment(s)

Patients presenting with symptoms concerning for CAD are a common and challenging problem for physicians. This is made more difficult when trying to interpret the meaning of various modalities of cardiac stress testing due to the fact that a specific type of stress test may be more appropriate in certain populations of patients. These papers each have inherent weaknesses but all point to a similar conclusion. Further studies may be needed to definitively answer this question.

Clinical Bottom Line

Numerous studies, including a meta analysis, show that while a positive stress test can be very useful in determining the next appropriate step of a patients care, a negative stress test may not be as useful. Patients with a recent negative stress test may be at the same risk for CAD as those without previous testing.

References

1. Walker, Jonathan DO. Galuska, Michael MD, Vega, David MD Coronary Disease in Emergency Department Chest Pain Patients with Recent Negative Stress Testing Western Journal of Emergency Medicine, Department of Emergency Medicine (UCI), UC Irvine 2010; 11(4):384-388
2. Rebecca H Nerenberg BS, Frances S. Schofer PhD, Jennifer L. Robey RN, Aaron M. Brown BS, Judd E. Hollancer MD Impact of a negative prior stress test on emergency physician disposition decision in ED patients with chest pain syndromes The American Journal Of Emergency Medicine, Elsevier Inc.
3. A. Banerjee1, D.R. Newman, A. Van den Bruel, C. Heneghan Diagnostic accuracy of exercise stress testing for coronary artery disease: a systematic review and meta-analysis of prospective studies The International Journal of Clinical Practice